In a small Dutch oven or heavy soup pot, melt the butter over medium heat. With a wooden spoon, stir in the flour, and keep stirring until the butter and flour combine. Add the leek, and continue stirring. The mixture will be very dry, so be sure it doesn't burn. Cook for 1-2 minutes, until the leek begins to get translucent.

Stir the adobo sauce into the chicken stock, and pour the mixture into the pot. Stir to break up any clumps. After the soup boils, reduce heat to low, and add the corn, orzo, salt and pepper. Cook, stirring frequently and scraping up any bits that stick to the bottom of the pan, for 10 minutes, until the orzo is almost soft. Add the salmon and the cream or milk. Stir, and cook over low heat, giving an occasional stir, for 5 minutes or until the fish is cooked and breaks up easily. Taste, and adjust with more black pepper, if needed.